喷灌不同水肥处理下紫花苜蓿光合特性、叶绿素荧光参数及产量变化

Changes of Photosynthetic Characteristics,Chlorophyll Fluorescence Parameters and Production of Alfalfa Under Different Water and Fertilizer Treatments Under Sprinkler Irrigation

为揭示喷灌不同水肥处理对中低产田紫花苜蓿光合特性、叶绿素荧光参数及生物量的影响,在丰乐河灌区试验推广基地开展紫花苜蓿喷灌不同水肥处理田间试验,结果表明:灌水和施氮水平对植物光合作用有显著影响,随着灌水量的减少,影响紫花苜蓿的光合特性的因素由气孔限制逐渐转变为非气孔限制;叶绿素也随灌水量的减少而减少,中肥处理叶绿素含量高于高肥处理和低肥处理,中肥中水1处理的苜蓿叶绿素含量最高;随着灌水量的减少,Fv/Fm、ETR、Fv、Fm、Fv/Fo、ΦPSⅡ均降低,产量也降低,综合分析,中氮中水1处理效果最佳,因此建议该地区紫花苜蓿可参照中氮中水1处理灌水施肥模式,灌溉定额为416.8 mm,施氮量为206.6 kg/hm^(2)。

In order to reveal the effects of different water and fertilizer treatments of sprinkler irrigation on the photosynthetic characteristics,chlorophyll fluorescence parameters and biomass of alfalfa in low-yield fields,a field experiment with different water and fertilizer treatments of alfalfa was carried out in the experimental extension base of Fengle River Irrigation District.The results showed that irrigation and nitrogen application levels had significant effects on plant photosynthesis.With the decrease of irrigation amount,the factors affecting photosynthetic characteristics of alfalfa gradually changed from stomatal limitation to non-stomatal limitation.The chlorophyll content in medium fertilizer treatment was higher than that in high fertilizer treatment and higher than that in low fertilizer treatment.The alfalfa chlorophyll content in the medium fertilizer treatment 1 was the highest;with the decrease of irrigation amount,Fv/Fm,ETR,Fv,Fm,Fv/Fo,ΦPSⅡall decreased,and the yield also decreased.Comprehensive analysis shows that medium nitrogen medium water treatment 1 has the best effect.Therefore,it is suggested that alfalfa in this area can refer to the mode of irrigation and fertilization under medium nitrogen medium water treatment 1,with irrigation quota of 416.8 mm and nitrogen application rate of 206.6 kg/hm^(2).